Devices which measure a physiological variable of a user and which then provide feedback to the user for the purpose of modifying the variable are well known in the art. U.S. Pat. Nos. 5,076,281, 5,800,337 and 6,090,037 to Gavish, which are incorporated herein by reference, describe methods and devices for modifying biorhythmic activity by measuring one or more variables of a user. The patents describe the generation of a stimulus, which is provided to the user, so as to change the biorhythmic activity of the user in a way that is related in a predetermined way to the monitored biorhythmic activity.
U.S. Pat. No. 5,423,328 to Gavish, which is incorporated herein by reference, describes a stress-detecting device for monitoring respiration, and, in particular, a method for detecting and monitoring circumferential changes in the chest or abdomen of a user resulting from breathing. U.S. Pat. No. 4,580,574 to Gavish, which is incorporated herein by reference, describes a method for non-invasively monitoring properties of living tissue.
U.S. Pat. No. 6,090,037 to Gavish, which is incorporated herein by reference, describes techniques for modification of rhythmic body activity of a user by monitoring biorhythmic activity of the user, and providing the user with a stimulus pattern that resembles but differs from the monitored biorhythmic activity in a way that when followed voluntarily by the user drives a change in the biorhythmic activity.
PCT Patent Publication WO 01/02049 to Gavish et al., which is assigned to the assignee of the present patent application and is incorporated herein by reference, describes techniques for facilitating improving health of a user, including a first sensor, adapted to measure a first physiological variable, which is indicative of a voluntary action of the user, a second sensor, adapted to measure a second physiological variable, which is not entirely under the direct voluntary control of the user, and circuitry, adapted to receive respective first and second sensor signals from the first and second sensors, and responsive thereto, to generate an output signal which directs the user to modify a parameter of the voluntary action. The '049 publication also describes an interventive-diagnostic system comprising a local computing device at a local site, which applies an intervention to a user at the site and receives, from one or more sensors attached to the user, one or more input signals indicative of a physiological condition of the user. One preferred embodiment described includes monitoring breathing movements using one sensor, and guiding the user to modify a breathing pattern in an attempt to optimize blood oxygenation, as measured by a second sensor.
An abstract entitled, “Repeated blood pressure measurements may probe directly an arterial property,” American Journal of Hypertension (April, 2000); 13(4), part 2: 190A, by B. Gavish, which is incorporated herein by reference, proposes that the slope of a line relating multiple systolic and diastolic blood pressure measurements is a physiologically-meaningful parameter.
An article entitled, “Challenges facing 3-D audio display design for multimedia,” Journal of the Acoustical Society of America (1999); J 105:1357, by D. R. Begault, which is incorporated herein by reference, describes the production and psychophysiological implications of 3-D sound, which enables listeners to perceive the direction of a sound source in three dimensions. Another article, entitled, “Localization using nonindividualized head-related transfer functions,” by Wenzel et al., Journal of the Acoustical Society of America (July, 1993); 94(1), pp. 222-234, which is incorporated herein by reference, describes the synthesis of 3-D sound, so as to enable listeners to perceive the 3-D direction and localization of a virtual sound source. In addition, a cassette distributed by NASA/Ames Research Center, entitled, “Demonstration of 3-D auditory display,” allows a listener using a normal cassette player and standard earphones to experience the three-dimensional effect.
Other articles of interest, all of which are incorporated herein by reference, include:
(a) an article by Cooke et al., entitled, “Controlled breathing protocols probe human autonomic cardiovascular rhythms,” American Journal of Physiology, (1998); 274:H709-H718
(b) an article by Pitzalis et al., entitled, “Effect of respiratory rate on the relationship between RR interval and systolic blood pressure fluctuations: a frequency-dependent phenomenon,” Cardiovascular Research (1998); 38:332-339
(c) an article by Bernardi et al., entitled, “Effect of breathing rate on oxygen saturation and exercise performance in chronic heart failure,” The Lancet (May 2, 1998); 351:1308-13
(d) an article by Mortara et al., entitled, “Abnormal awake respiratory patterns are common in chronic heart failure and may prevent evaluation of autonomic tone by measures of heart rate variability,” Circulation (Jul. 1, 1997); 96:246-252
(e) an article by La Rovere et al., entitled, “Baroreflex sensitivity and heart-rate variability in prediction of total cardiac mortality after myocardial infarction,” The Lancet (Feb. 14, 1998); 351:478-484
(f) an article by Gimondo and Mirk, entitled, “A new method for evaluating small intestinal motility using duplex Doppler sonography,” AJR American Journal of Roentgenology (January, 1997); 168(1):187-192.
Devices which are at least partially operated remotely are also known in the art. U.S. Pat. No. 4,102,332 to Gessman, which is incorporated herein by reference, describes a device for remote telephonic resuscitation. The device includes an electrocardiograph and a defibrillator which are carried by a user with a known history of cardiac symptoms, and which may be used to diagnose and treat acute cardiac symptoms. In order to facilitate the diagnosis and treatment, the device may be connected to a telephone line, so that a remote physician may make the diagnosis and perform the treatment.
U.S. Pat. No. 4,195,626 to Schweizer, which is incorporated herein by reference, describes a biofeedback chamber for applying audible, visual electrical or tactile stimuli to a subject according to a rhythmic pattern. The subject's reactions are measured, analyzed and used to control the stimuli.
U.S. Pat. No. 5,782,878 to Morgan, which is incorporated herein by reference, describes a system including an external defibrillator, a defibrillator communicator, and a communication network. In order to perform a defibrillation, information is transmitted back and forth between a patient and a communication station.
U.S. Pat. No. 5,794,615 to Estes, which is incorporated herein by reference, describes a system for treatment of congestive heart failure. The patent describes controlling the flow rate of a pressurized gas delivered to a patient during the two phases of the respiratory cycle independently. The system may be fully automated responsive to feedback provided by a flow sensor that determines the estimated patient flow rate.
U.S. Pat. No. 5,678,571 to Brown, which is incorporated herein by reference, describes a method for treating a medical condition in a patient comprising choosing a psychological strategy for treating the medical condition, and then encoding electronic instructions for an interactive video game. The game implements the psychological strategy, and loads the electronic instructions into a microprocessor-based unit equipped with a display for displaying the video game. The game contains scoring instructions to quantitatively analyze the medical condition of the patient, counseling instructions and self-care instructions. The video game can be used in conjunction with a physiological variable measuring device connected to the microprocessor-based unit.
U.S. Pat. No. 5,596,994 to Bro, which is incorporated herein by reference, describes an automated and interactive positive motivation system that allows a physician, counselor or trainer to produce and send a series of motivational messages and/or questions to a client to change or reinforce a specific behavioral problem.
U.S. Pat. No. 5,752,509 to Lachmann et al., which is incorporated herein by reference, describes a system for artificially ventilating a patient. The ventilation system has a gas delivery unit for delivering controllable inspiration pulses to a patient, a monitoring unit for measuring at least one parameter related to the function of the circulatory system, such as a blood gas analyzer, and a control unit for determining an optimal peak inspiratory pressure and pressure amplitude for the inspiration pulse, based on the measured circulatory system parameter.
Descriptions of respiratory monitoring apparatus which assess capacitance are found in U.S. Pat. No. 5,485,850 to Dietz, U.S. Pat. No. 4,033,332 to Hardway et al., U.S. Pat. No. 4,381,788 to Douglas, U.S. Pat. No. 4,474,185 to Diamond, and in U.S. Pat. Nos. 5,367,292, 5,070,321, and 5,052,400, all of which are incorporated herein by reference.
U.S. Pat. No. 5,690,691 to Chen et al., which is incorporated herein by reference, describes a portable or implantable gastric pacemaker, which includes multiple electrodes that are positioned on an organ in the gastrointestinal (GI) tract, so as to deliver electrical stimulation to pace the peristaltic movement of material through the GI tract.
U.S. Pat. Nos. 5,590,282 and 4,526,078, which are incorporated herein by reference, describe techniques for causing a computer to compose music.
U.S. Pat. No. 4,883,067 to Knispel et al., which is incorporated herein by reference, describes a method for translating a subject's electroencephalogram into music, so as to induce and control various psychological and physiological states of the subject.
U.S. Pat. No. 4,798,538 to Yagi, which is incorporated herein by reference, describes an abdominal respiration training system. The state of the abdominal respiration of a person is measured by a sensor attached to the abdominal region, and the detected breath pattern is compared with an ideal breath pattern.
U.S. Pat. No. 5,827,179 to Lichter et al., which is incorporated herein by reference, describes a real-time biological data processing PC card, adapted to input and process biological data from one or more biological data sensors, and to be interchangeable with other real-time biological data processing PC cards.
U.S. Pat. No. 6,050,940 to Braun et al., which is incorporated herein by reference, describes a general-purpose, low-cost system that provides comprehensive physiological data collection, with extensive data object oriented programmability and configurability for a variety of medical as well as other analog data collection applications.
U.S. Pat. No. 6,001,065 to DeVito, which is incorporated herein by reference, describes techniques for measuring and performing real-time FFT analysis of bioelectrical signals such as electroencephalogram (EEG) and electromyography (EMG) signals for the control of systems. Passive and active interaction with various electronic media such as video games, movies, music, virtual reality, and computer animations is also described.
In a number of cardiovascular diseases, including CHF, and pulmonary diseases, including COPD, breathing patterns display irregularities. These irregularities are known markers for disease-related mortality and morbidity. Typical irregularities include Cheyne-Stokes breathing (recurrent episodes of central apnea alternating with hyperpnea), amplitude-modulated breathing (periodic breathing) at a rate of about one modulation per minute, repeated sighs, and breathing at random amplitudes and periods. A reduction in breathing pattern irregularity indicates an improvement in health. The impairment of cardiovascular reflexes, which control blood pressure and volume in attempt to minimize fluctuations in blood supply to organs (homeostasis), is also clinically significant in cardiovascular and psychosomatic diseases.